// In header: <boost/log/utility/manipulators/add_value.hpp>
template<typename RefT> 
class add_value_manip {
public:
  // types
  typedef RefT                                                                 reference_type;  // Stored reference type. 
  typedef remove_cv< typename remove_reference< reference_type >::type >::type value_type;      // Attribute value type. 
  // construct/copy/destruct
  add_value_manip(attribute_name const &, reference_type);
  // public member functions
  attribute_name get_name() const;
  get_value_result_type get_value() const;
};